The incident occurred in the eastbound lanes about 2 p.m. near the Lee Road exit.

Witnesses say the gunman was weaving in and out of traffic in a black Porsche Cayenne Turbo sports utility vehicle with dark-tinted windows and a chrome roof rack.

He had some type of driving altercation with the victim's friend or family member traveling in a third vehicle, said Jim Solomons, a spokesman for the Orange County Sheriff's Office.

In retaliation, the victim cut in front of the Porsche. That's when the driver pulled out a gun, firing at least five times into the back of the victim's truck.

The Porsche kept heading east toward Daytona Beach, Solomons said.

The victim was able to stop his truck while someone else called 911. He was taken to Orlando Regional Medical Center.

Eastbound traffic was backed up for hours as authorities investigated the incident.

Investigators think the Porsche was traveling on Florida's Turnpike before getting on I-4. Before the shooting, other motorists had alerted authorities that the Porsche was moving erratically through traffic, Solomons said.

The incident should remind drivers how serious driving altercations can become and motorists should be careful, Solomons said.

In February, a 36-year-old Land O' Lakes man was fatally shot on the side of I-4 after he cut off another driver after the Daytona 500.